Just when you thought it was safe to go back in the water...
L.A. Daily News reports that some 42 million gallons of raw sewage has made its way into the Pacific Ocean through L.A.'s storm drains and rivers since 2007, or roughly 2/3 of the 70 million gallons of total sewage unleashed through spills, according to the county Public Health Department.
Even worse, 25 million of this tremendous amount of wayward sewage was spilled into our waterways in 2021 alone, stemming from such calamities as the failure of the Hyperion Water Reclamation Plant in July 2021 and six months later, a sewage system collapse in Carson this past December that closed multiple beaches from O.C. to L.A.
Officials for our sanitation agencies say 2o21 was simply an anomaly, given that no other year in this 15-year period saw more than 10 million gallons of raw sewage released into our oceans, anything less than 10 million gallons being apparently acceptable. Guessing they don't surf.
Public health data suggests that spill incidences have gone down by 70% since 2008, while the ugly side of that coin finds spill volume spiking in recent years and less of the spillage being kept out of the ocean. About 92% of the 42 million cited gallons spilled into a waterway connected to the sea happened after 2015.
So what the Hell is going on?
A majority of raw sewage spills in SoCal are attributed to clogs in sewer systems caused by blockages by "grease and roots." But the biggest spills by volume are linked to infrastructure failings that are preventable, which make up about 4% of the 6,412 total spills but are responsible for 63% of the total gallons spilled into the sea.
The Carson spill is being pinned on a sewer pipe that was almost 60 years old, recalling L.A.'s even more ancient water main lines that always seem to be busting, liberating torrents of our precious, disappearing water onto L.A.'s streets. A Carson resident spotted sewage seeping from a manhole at a busy local intersection, which was traced back to a sinkhole and collapsed sewer said to be part of the cause of some 8.5 million gallons of raw sewage leaking into the Dominguez Channel.
The Carson spill kicked off an ongoing countywide assessment of the county's sewer infrastructure, trying to prevent such avoidable accidents in the future by updating aging equipment, among other sensible practices. Only one-third of the planned replacement of the failed sewer had been achieved at the time of its collapse, with officials blaming design and permitting complications.
While sewage lines are scheduled for inspection every 15 years, which is typically executed via camera, some lines are too lengthy for the cameras to fully explore, leaving some lines unexamined for over 50 years. Concrete corrosion caused by some of the noxious chemicals in sewage is one of many possible phenomena that may be causing sewer collapses and failure.
A UCLA civil and environmental engineering professor who helped form the report on the Hyperion plant spill also questions whether low-flow orders to help conserve water are increasing the accumulation of heavy materials that lead to clogs.
New technologies to both inspect and secure sewer lines are being explored and tested.
The spill at El Segundo's Hyperion Water Reclamation Plant, one of the country's largest, was the worst in the 15-year period being reviewed, caused by the failure of screens and chopper pumps that normally divide trash and large debris from incoming sewage. The resulting clog caused water to rise rapidly inside the plant, escaping the attendant operators' attentions, despite visible alarms. Simultaneously, a computer system that should have alerted the plant's head operator was yet to be fully installed.
As a result, 17 millions gallons of raw sewage was released right into the ocean to save the plant, followed by more, partially treated sewage that was released through a pipeline extending 5 miles into the ocean during the months of repair that came afterward.
So far, the report says the impact from these larger, recent spills is yet to be fully grasped. Los Angeles Sanitation and Environment (LASAN), which operates the Hyperion plant, claims that preliminary, incomplete testing from trawling that started in late 2021 shows "no negative impacts to fish and other wildlife" from the 17 million gallons intentionally released near the plant.
LASAN officials say we may need more than a year to study the full impact. An early city report initially showed a rise in e.coli and enterococcus bacteria at 3,200% above water quality standards. Such a bacteria spike could pose a risk to sea life by "blanketing" the sea floor, " clogging fish gills, creating dead zones, and blocking sunlight," even though LASAN claims the increase in bacteria was found in a layer of the ocean known as the thermocline, which prevents the nasty little life forms from hitting our beaches.
Meanwhile, Heal the Bay water quality scientist Luke Ginger tells Daily News it will take years of well-funded research to asses the full impact of the Hyperion spill, saving his final say until the testing is done and the data released to the public.
